Nitroglycerin, or glonoin, (C3H5(N03)3 = 255.44) is obtained by mixing glycerin with nitric and sulphuric acids.

Pharmacodynamics.

Central nervous system is not affected directly.

Muscular system unaffected. Depression of unstriated muscle.

Respiration is slightly accelerated and deepened, probably as a result of diminished oxidation.

Heart is accelerated from depression of the inhibitory center, possibly by some balancing action to counter the fall in blood-pressure.

Blood-pressure is greatly diminished from direct detonizing effect on the unstriated muscle of the arteries and veins, especially of the splanchnic and cerebral areas, and the blushing area of the face and neck.

Eye. - Some disturbance of the color sense, probably centric. Increased intraocular tension.

Alimentary Tract. - No effect apparent.

Secretory Glands. - Kidney action inconstant.

Metabolism. - No constant change determinable. Methemoglobin formed.

Temperature is slightly decreased from capillary dilatation.

Absorption. - Rapid.

Excretion. - By urine, as nitrates and nitrites.

Tolerance is fairly rapidly acquired.

Blood is slightly altered by the change of oxyhemoglobin to methemoglobin and nitric-oxide-hemoglobin.

Symptoms.

Therapeutic Doses.

Flushing of face. Pressure in the head. Vertigo.

Accelerated pulse. Deeper, quicker respiration. Possibly an intense frontal headache.

Toxic Doses (in animals).

Violent panting respiration. Loss of muscular power. Wildly beating heart. Failure of respiration. Collapse.

Therapeutics.

The nitrites are of value in conditions accompanied by abnormally high blood-pressure.

Dosage.

Spiritus Glycerylis Nitratis, 0.03 to 0.2 mil.

Tabellae Trinitrini, each contain 0.0006 Gm. of nitroglycerin; 1 to 2 tablets.

Note. - Symptoms produced by the several nitrites are similar. Amyl Nitrite acts most rapidly, and produces the maximum of flushing; it is also most fleeting. Glonoin is much more prolonged in its action, and is liable to be followed by a severe headache until one has become accustomed to the drug.

Nitroglycerin 73

Violet = depression.